He parked at his office and left the car with the child still secured in his rear-facing car seat. Harris returned to his car around lunch time,
http://www.usatoday.com/story/news/...ar-dad-visited-car-in-middle-of-day/11350773/
According to the warrant, Harris parked his vehicle at his place of employment with his son strapped into a child seat in the rear seat of the car, and then went to work for the day.
Harris then returned to the car at lunch, opening the door and placing an object in the vehicle before shutting the door and returning to work, while his child remained strapped in the back seat, the warrant states.
http://blogs.findlaw.com/blotter/20...car-death-why-is-dad-charged-with-murder.html
so far not finding anything stating the parking lot was some distance from the building in which dad work, and for sure not finding anything substantiating it was a ten minute walk. Even if the parking for his building is located across a street or a short distance I can't see that being a ten minute walk so I think this was probably just speculation.